The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 10, 2005
Filed:
Jun. 20, 2001
Kensaku Komatsu, Kurashiki, JP;
Ichirou Kawata, Okayama, JP;
Shigenobu Ishii, Kurashiki, JP;
Yoshio Sato, Kurashiki, JP;
Seiichi Nakahara, Osaka, JP;
Kensaku Komatsu, Kurashiki, JP;
Ichirou Kawata, Okayama, JP;
Shigenobu Ishii, Kurashiki, JP;
Yoshio Sato, Kurashiki, JP;
Seiichi Nakahara, Osaka, JP;
Kuraray Co., Ltd., Kurashiki, JP;
Abstract
A porous hollow fiber membrane having a particle cutoff within the range of 1 to 10 μm and a pure water permeate flow equal to or higher than 30,000 L/m/hr/100 kPa. This porous hollow fiber membrane can be prepared by a method including, while a spinning dope containing a base polymer as a material for forming the porous hollow fiber membrane, an additive used for facilitating a phase separation of the spinning dope, a solvent compatible with both the base polymer and the additive and a mass of microparticles insoluble to the compatible solvent and uniformly dispersed in a liquid medium and having an average particle size within the range of 1 to 20 μm, and a coagulating liquid for forming the hollow fiber membrane is used, a step of forming the hollow fiber membrane according to a dry-wet spinning method or a wet spinning method, and a step of extracting and removing the microparticles by immersing the hollow fiber membrane, which has been spun, into an extracting solution effective to dissolve the microparticles, but ineffective to dissolve the base polymer.